Battery Chargers - Solar Chargers to Buy, Chargers to Hack, And Concept Chargers to Wait For

One of the ways to green up gadgets that require batteries is to use rechargeable batteries and practice habits that make your batteries last as long as possible. But if you're using rechargeable batteries, you're still likely juicing them up with power from the grid - the coal-burning grid. Here are some great options for getting off grid power for your rechargables - including chargers you can hack yourself from stuff around the house - and some really cool concepts for battery chargers that we might see one day.

Battery Chargers You Can Buy Today

Duracell GoMobileThe GoMobile by Duracell is a compact option for charging four batteries at once in under an hour, either via wall plug or in the car with an adapter. It comes a solid review of the charger shows that it holds up well, and for $30, it's not a bad option; however, we prefer chargers that take you off grid. They're slower, but better on the environment.

PowerFilm Solar ChargersPowerFilm is a somewhat pricey, but very high quality option. We spotted these at the Consumer Electronics Show back in January, and while they seemed large, both in size and price, they also are clearly worth it if you're looking for high end battery chargers. They'll charge 2 AA batteries in about 3 hours of direct sunlight, or 4 AA batteries in about 7 hours. They run around $90.

Sunbender Build-it-Yourself Solar Battery Charger KitsIf you want to customize your solar battery charger, you can check out this DIY kit. Running you anywhere from $12 to $40, you can create your own reasonably modest or Tim-The-Tool-Man-Taylor-Grunt-Inducing battery chargers for AA's or AAA's.

Energizer Solar ChargerIf you're willing to either wait, or order from overseas, you can get the Energizer Solar Charger. This debuted early in the year at the Consumer Electronics Show, and so far hasn't made it to the US market, though it's probably only a matter of time. It runs around £63, which factoring in conversion and shipping, you might as well just buy the PowerFilm solar roll.

There are quite a few more options from Sundance Solar for solar battery chargers. Plan to spend around $100 if you want to use the sun to juice up your batteries. A little on the pricey side upfront, but you're basically harvesting free power for years if you go the solar route.

Battery Chargers You Can Make Yourself For Next to Nothing

From a Solar Yard LightThis handy hack was discovered after a friend rolled over Trevor's solar garden light. Turns out you don't need to do much more than just run over a garden light, put in your run-down batteries, set it out in the sun and wait. Simple!

From a Hand-Crank FlashlightIf you have a spare hand-crank flashlight then you'll have everything you need to switch it to a battery charger. The video shows how to turn it into a cell phone charger. However, swap out the plug type and attach it to a AA-style battery charger and voila! You're in business.

Concept Battery Chargers That Are Cool, But We'll Probably Never See

Febot, the Flying Battery ChargerThis design is...odd. It looks a bit like a tampon with twirly wings and a suction cup attached. The battery goes inside, and you suction it to a window, or window ledge, and let the passing wind do the recharging. It's clever, but we aren't sure that those little turbine blades would really do the trick, especially placed so close to the base.

Hand-Crank One Battery At a TimeThis design isn't exactly different from any other hand-crank battery charger, except for one thing that will probably keep it from ever having a successful time in the marketplace...it charges just one little battery at a time.

The reNEW Solar Battery ChargerThis design looks just plain cool. It is a frame-like solar charger that could be suctioned to a window, or propped up on a desk while gathering sunlight and recharging your batteries. The batteries are stored in a compartment in the back, so all you really see is the solar panel, which looks a bit like a piece of art. Much more attractive than the clunkier solar chargers on the market right now.

Shake Some Energy Into Your BatteriesThe Shakenergy is a neat idea, though it has the same downfall as the hand-crank idea...it takes energy to make energy. The idea is to make batteries with recharging components within the battery itself, so as they run out of juice, you simply shake them and the kinetic action recharges them.